1. Field of the Invention
Fold over of paper webs in the printing industry has long been done but as stated in our earlier U.S. Pat. No. 3,799,536 on PAPER FOLDER the length of run necessary to effect such a fold over was substantial. In our earlier patent it was shown how the fold over process or the superimposing of one sheet of paper web over another was accomplished in just a few short feet. However, this foreshortening of the paper turning process has presented many more problems to the printer and to the machine operator. In earlier full bay turning the paper webs were given adequate space in which to self adjust when the paper turning plows were not accurately adjusted. Now with short space turning, accuracy of plow adjustment is extremely critical. Without this accurate adjustment of the plow the paper web easily becomes wrinkled either at the point of paper turn over or at the point of pulling of the paper between pinch rollers. It is not always good enough to accurately square the plow with the machine frame because the paper web itself may be out of square or may have some "camber" in it. Thus the present invention concerns itself with a fully and accurately adjustable paper plow.
2. Description of the Prior Art
In addition to the PAPER FOLDER U.S. Pat. No. 3,799,536 of Clyde G. Gregoire mentioned above, applicants call attention to the following prior art which would appear to have a bearing on the subject application.
The patent to Potdevin U.S. Pat. No. 1,975,121 entitled TUBE MAKING MACHINES shows and describes a laterally adjustable paper forming mechanism which permits the device to form various diameters of paper tubes.
The patent to Strain U.S. Pat. No. 1,982,703 entitled FORMER FOR PRINTING MACHINES shows and describes a device for folding paper upon itself in a printing machine. The Strain device includes a nose folder which is mechanically laterally adjustable and further is itself inherently elastic, flexible and yielding so that it is automatically self adjustable to prevent the buckling of the paper web being folded.
Hitner U.S. Pat. No. 2,204,274 entitled WAX PAPER FOLDING MACHINE illustrates a thin forming plate 42 acting in conjunction with deflecting and pressure rollers to accomplish a fold over of a paper web. Although this Hitner device shows the environment it lacks any disclosure of an adjustable paper plow.
The Haas et al U.S. Pat. No. 2,660,219 entitled HEAT-SEALING MACHINE shows and describes a paper former which is laterally and vertically adjustable. Flexibly mounted pressure rollers are adjustable and combine with the adjustable former to fold the paper web over upon itself. Despite the fact the Haas et al paper former is somewhat adjustable it is so rigid in many respects that it cannot be adjusted to compensate for irregularities in the paper web being folded.